Of note, when expressing RARα and RARαS77A in parallel in RA-resistant AML cell line harboring a defective RARα ligand binding domain or in embryonic teratocarcinoma RARα−/− stem cells, RARαS77A, but not RARα, inhibited proliferation without a need of RA stimulation [21]. This evidence concerns the gene RARA and acute myeloid leukemia.